1. Field of the Invention
The present application relates to methods and systems for selectively sealing areas of curtain walls and more particularly, but not by way of limitation, to methods and systems for sealing junctions between horizontal and vertical support members of curtain walls during construction.
2. History of the Related Art
Building curtain-wall technology is well known and accepted in the industry. Curtain walls are typically constructed of, for example, extruded aluminum support members having generally U-shaped channels (although other shapes may be utilized) for supporting a plurality of panel members. The plurality of panel members serve as an exterior of a building and are usually panes of glass, and often double-pane glass sections, but other building materials such as, for example, aluminum, granite, slate, or concrete may be utilized. The plurality of panel members are often of identical size and shape. However, near doors, opening windows, and other access points into the building, panel members of different sizes and shapes may be utilized.
Curtain walls generally include a horizontal member intersecting with a vertical mullion at a junction. The junction typically requires cutting of at least a portion of the horizontal member around the vertical mullion. Sealing is often required between a cut portion of the horizontal member and the vertical mullion to prevent infiltration of, for example, water and other contaminants into the junctions. In many curtain-wall systems, a plug is inserted into a gap formed between a cut edge of the horizontal member and the vertical mullion. After insertion of the plug, the edges of the plug are sealed with a sealant such as, for example, silicone.
In many instances, edges of the horizontal member, the vertical mullion, and the plug are not precisely square due to, for example, human error or manufacturing limitations. These imperfections cause crevices to be present within the junctions. Furthermore, profile contours associated with the horizontal member, the vertical member, and the plug also create crevices. These crevices are often quite small and, in many cases, are nearly imperceptible to the human eye. Such crevices may, however, be sufficient to permit infiltration of water into the curtain-wall system. In addition, the crevices often make accurate placement of sealant difficult and time consuming due to an inability of a worker to see the crevices. Larger crevices are often more visible to a worker and, thus, more effectively sealed. Furthermore, larger crevices permit better infiltration of sealant thereby creating a better seal.